Base SAS ５
The following SAS program is submitted:
data work.sets;
do until (prod gt 6);
prod + 1;
end;
run;
Which one of the following is the value of the variable PROD in the output
data set?
A. 5
B. 6
C. 7
D. 8
Click Comment link to get answer
答案是７。我有点不清楚这个７具体指的是什么？
（１）ＤＯＵＮＴＩＬ一直到ｐｒｏｄ＝６ ｐｒｏｄ＋１＝６＋１＝７
（２）ｄｏｕｎｔｉｌ一直到检查到ｐｒｏｄ＝７才会不执行，ｐｒｏｄ＝７
请问这里的ｖａｌｕｅ ｏｆ ｐｒｏｄ ｉｎ ｔｈｅ ｏｕｔｐｕｔ是指第一种还
是第二种，我觉得是第一。因为这里指的是ｏｕｔｐｕｔｄａｔａ．
求教！谢谢！
n***8 发帖数: 39
2
do until 是先做再检查，从（1）到（2）。
B*H 发帖数: 10
3
第一种. do until 不累加. If prod + 1 is not included, the program will run
forever.
【在 r**********y 的大作中提到】 : Base SAS ５ : The following SAS program is submitted: : data work.sets; : do until (prod gt 6); : prod + 1; : end; : run; : Which one of the following is the value of the variable PROD in the output : data set? : A. 5
